Usually, in the field of flush toilets, a drain trap formed of S-shaped pipe is provided between the toilet and the drainpipe, in which sealing water prevents reverse flow of offensive odors from the drainpipe. When sewage water is drained through a drain trap having this structure, however, sewage water must be speeded by utilizing the pipe head, which causes the problems that the total vertical length of the drainpipe must be long and that it is often clogged up with waste matter.
To solve such disadvantages of drain traps, Japanese Patent Publication No.50-11188 and Japanese Patent Laying-Open No.53-98137 disclose flush toilets, and Japanese Patent Laying Open No.3-186265 discloses a care bed. The inventions of the first and third references suggest structures of odor-sealing valves in which a rubber tube etc. provided in a drainpipe is filled with air from an air pump etc. to close the drain hole and is evacuated to open the drain hole. The invention of the second reference suggests an odor-sealing valve in which a hole is opened/closed with a hemispherical member turned by a foot pedal.
However, according to the inventions of the first and third references, parts like the air pump and air piping complicate the structure, and the use of a rubber tube susceptible to deterioration in a moving part requires difficult process for fabricating the odor-sealing valve and its vicinity and troublesome maintenance. Also, the invention of the second reference encounters the same problems because of the presence of a mechanism for opening/closing the hole. Further, in any of the background arts, when excrement adheres to the upper part of an odor-sealing valve, this surface attaches on the toilet bowl side, which causes unpleasant feeling.
With the conventional care bed according to the third reference, odors in defecation are not sufficiently prevented from spreading. Further, according to the conventional care bed of the third reference, it is necessary to previously, before defecation, evacuate the rubber tube located in the position of buttocks to open the toilet seat, and therefore it does not work when a patient unintentionally defecates. Further, with the conventional care bed, it is necessary, when bathing a patient, to remove the patient from the bed to another place, which heavily burdens the nursers.
Considering the problems of the background arts, an object of the present invention is to provide a flush toilet having an odor-sealing valve which can be certainly opened/closed with a simple structure and enables easy maintenance.
Another object of the present invention is to provide a flush toilet which does not allow adhering waste matter to face toward the bowl of the toilet.
Still another object of the present invention is to provide a flush toilet which can effectively work when a patient etc. unintentionally defecates.
An object of a care bed apparatus of the present invention is to reduce physical burden on nurses when bathing a patient, as well as enabling the above-mentioned rational means for dealing with defecation.